This invention relates to information transmission systems and more particularly to an infrared information transmission system with a portable battery operable transmitter.
Infrared information transmission systems have proved invaluable for short-range transmission of both analog and digital information. The inherent advantages of infrared transmission are apparent; transmission of infrared data does not generate radio frequency interference which might interfere with other instrumentation; and, even more important, the infrared receiver is unaffected by radio frequency interference produced by other devices present. One known system which utilizes infrared transmission of analog information is a music system in which an infrared transmission is connected to a high-fi, stereo or other music production amplifier apparatus, and a portable receiver is incorporated in a headphone set. Music is transmitted via infrared energy anywhere within the confines of the room in which the transmitter is placed. The transmitter of these prior art systems, however, is not portable; the modulated FM plus AM envelope approach utilized, requires a relatively large quantity of power to transmit infrared signal, and therefore, as a practical matter, cannot be operated from battery power with any expectation of a reasonable battery lifetime.
In particular, such applications as a portable transmitter which transmits infrared information from a plurality of sensors or medical electrodes attached to a patient to provide information to a remote monitor, by means other than conventional wires, is not feasible using the prior art system; nor are portable hand-held analog-digital transmitters utilized for video games or television on/off/channel selection capable of being provided utilizing infrared energy transmission. A portable telephone which both receives and transmits information which is connected to the main telephone lines via radio frequency signal transmission is either very expensive or is not capable of eliminating unwanted interference; infrared transmission has not previously been appropriate for this application. In each of the above examples, the transmitter is required to be powered by a small number of batteries making the transmitter not only portable but also containable within a small (hand-held) package.
It is therefore an object of the present invention to provide an improved information transmission system.
Another object of the invention is to provide an improved infrared information transmission system.
A further object of the invention is to provide an infrared information transmission system with a portable transmitter.
Still another object of the invention is to provide an infrared information transmission system with a portable hand-held transmitter powerable by a battery power source.
It is a further object of the invention to provide an improved medical patient monitoring system.
Yet another object of the invention is to provide an improved wireless portable microphone or telephone.
It is yet a further object of the invention to provide an improved hand-held wireless remote control unit for video games, TV set control and the like.